In the field to which apparatuses that need to perform identity verification, such as cigarette vending machines and bank automatic teller machines, pertain, there has been proposed an apparatus configured to acquire a face image by capturing an image of a face of a person with a camera and estimates the attributes of the person such as age and sex from the face image (for example, Patent Document 1). Estimation of the attributes such as age can be achieved by, for example, a model learning procedure, which includes preparing a model with a machine that has learned a large number of pieces of sample image information and comparing an image of a subject whose attributes are to be estimated (referred to as “attribute estimation subject” hereinafter) with the model.